Scientists working in the Academy-funded Research Programme on Neuroscience (NEURO) have discovered important changes in the way that infants react to another person’s face at age 5–7 months.

Infants aged 5 months react very differently to a fearful face than those aged 7 months. “At the age of 7 months babies will watch a fearful face for longer than a happy face, and their attentiveness level as measured by EEG is higher after seeing a fearful than a happy face. By contrast, infants aged 5 months watch both faces, when they are shown side by side, for just as long, and there is no difference in the intensity of attention in favour of the fearful face,” said Mikko Peltola, researcher at the University of Tampere, at the Academy’s Science Breakfast this week.

It seems that at age 6 months, important developmental changes take place in the way that infants process significant emotional expressions. A fearful face attracts intense attention by the age of 7 months. In addition, it takes longer for infants to shift their attention away from fearful than from happy and neutral faces.

I wonder how much variability there is in when this transition happens. Also, do babies with Asperger's Syndrome or autism go through this same transition in how they react to fearful faces and do they do this at the same point in time as normal children?

Also, is the intense attention to fearful faces a defense mechanism? Or is it a pointless reaction at age 6 months but a capability that needs to come sooner or later which just happens to occur at 6 months?